Understanding the science behind noise measurements helps you interpret your evidence reports accurately.
A decibel (dB) is a logarithmic unit used to express ratio of two values of a physical quantity, often power or intensity. In acoustics, it measures sound intensity relative to a reference level.
The decibel scale is logarithmic, meaning every 10 dB increase represents a tenfold increase in sound intensity. For example, 80 dB is ten times more intense than 70 dB.
Where:
Your device's microphone captures raw audio samples from environment.
Root Mean Square (RMS) is calculated from audio samples to determine average sound energy.
A calibration offset (+80dB) is applied to convert the normalized RMS value to a decibel reading comparable to standard sound level meters.
The final decibel value is displayed and recorded for evidence generation.
Modern smartphone microphones typically measure within ±5dB of professional sound level meters. For absolute precision, use a calibrated Type 2 sound level meter.
For legal complaints, relative measurements and timestamped data are most valuable. Consistently elevated readings relative to the ordinance limit provide strong evidence, regardless of absolute calibration.
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